There are numerous compositions known to the art which can be compressed or tableted, providing a tablet, block or similar article which may be placed in the tank of a toilet and dispense cleaning active over a period of time. Such tablets may consist of, or include various cleaning agents such as bleaches, surfactants, disinfectants, and mixtures thereof. A particularly preferred disinfecting agent is an organic halogen source, and a particularly preferred family of organic halogen sources include halohydantoins. Halohydantoins are particularly preferred for the purpose as they are well suited to tableting and consequent slow release of halogen. Numerous prior art discloses halohydantoin based cleaning tablets for various uses, including U.S. Pat. Nos. 4,427,692; 4,537,697 and 4,560,766, all to Girard.
One of the difficulties associated with toilet bowl cleaning tablets of the art has been to establish a uniform release of active halogen over a commercially feasible term, for example, of two to four months. While dichloro, methylethyl or dimethyl hydantoins can be compressed sufficiently to permit such a long term release, for reasons of formulation efficacy and economics, pure dichloro, methylethyl or dimethyl, or other halohydantoins are not preferred. However sufficient tablet longevity is hindered when such tablets are not pure halohydantoin.
Accordingly, it is an object of the present invention to provide a composite tablet having longevity comparable to a pure halohydantoin tablet.
It is another object of the present invention to provide a composite tablet having cleaning performance comparable to that of a pure halohydantoin tablet.